A fuel cell stack of a solid polymer electrolyte type, for example, is provided by laminating modules, each of which is obtained by one or more cells superposed one on another, with each cell including a membrane-electrode assembly (MEA) and a separator. The MEA includes an electrolytic membrane that is provided by an ion exchange membrane, an electrode (an anode) formed of a catalytic layer and arranged on one surface of the electrolytic membrane, and an electrode (a cathode) formed of a catalytic layer and arranged on the other surface of the electrolytic membrane. This fuel cell stack is used by being accommodated in a fuel cell case (see, for example, JP H06-231795 A).